java.lang.Object
- org.apache.lucene.util.BitUtil

```
public final class BitUtil
extends Object
```
A variety of high efficiency bit twiddling routines.

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static long`	`deinterleave(long b)`	Extract just the even-bits value as a long from the bit-interleaved value
`static long`	`flipFlop(long b)`	flip flops odd with even bits
`static long`	`interleave(int even, int odd)`	Interleaves the first 32 bits of each long value Adapted from: http://graphics.stanford.edu/~seander/bithacks.html#InterleaveBMN
`static int`	`nextHighestPowerOfTwo(int v)`	returns the next highest power of two, or the current value if it's already a power of two or zero
`static long`	`nextHighestPowerOfTwo(long v)`	returns the next highest power of two, or the current value if it's already a power of two or zero
`static long`	`pop_andnot(long[] arr1, long[] arr2, int wordOffset, int numWords)`	Returns the popcount or cardinality of `A & ~B`.
`static long`	`pop_array(long[] arr, int wordOffset, int numWords)`	Returns the number of set bits in an array of longs.
`static long`	`pop_intersect(long[] arr1, long[] arr2, int wordOffset, int numWords)`	Returns the popcount or cardinality of the two sets after an intersection.
`static long`	`pop_union(long[] arr1, long[] arr2, int wordOffset, int numWords)`	Returns the popcount or cardinality of the union of two sets.
`static long`	`pop_xor(long[] arr1, long[] arr2, int wordOffset, int numWords)`	Returns the popcount or cardinality of A ^ B Neither array is modified.
`static int`	`zigZagDecode(int i)`	Decode an int previously encoded with `zigZagEncode(int)`.
`static long`	`zigZagDecode(long l)`	Decode a long previously encoded with `zigZagEncode(long)`.
`static int`	`zigZagEncode(int i)`	Same as `zigZagEncode(long)` but on integers.
`static long`	`zigZagEncode(long l)`	Zig-zag encode the provided long.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - pop_array
```
public static long pop_array(long[] arr,
                             int wordOffset,
                             int numWords)
```
    Returns the number of set bits in an array of longs.
  - pop_intersect
```
public static long pop_intersect(long[] arr1,
                                 long[] arr2,
                                 int wordOffset,
                                 int numWords)
```
    Returns the popcount or cardinality of the two sets after an intersection. Neither array is modified.
  - pop_union
```
public static long pop_union(long[] arr1,
                             long[] arr2,
                             int wordOffset,
                             int numWords)
```
    Returns the popcount or cardinality of the union of two sets. Neither array is modified.
  - pop_andnot
```
public static long pop_andnot(long[] arr1,
                              long[] arr2,
                              int wordOffset,
                              int numWords)
```
    Returns the popcount or cardinality of A & ~B. Neither array is modified.
  - pop_xor
```
public static long pop_xor(long[] arr1,
                           long[] arr2,
                           int wordOffset,
                           int numWords)
```
    Returns the popcount or cardinality of A ^ B Neither array is modified.
  - nextHighestPowerOfTwo
```
public static int nextHighestPowerOfTwo(int v)
```
    returns the next highest power of two, or the current value if it's already a power of two or zero
  - nextHighestPowerOfTwo
```
public static long nextHighestPowerOfTwo(long v)
```
    returns the next highest power of two, or the current value if it's already a power of two or zero
  - interleave
```
public static long interleave(int even,
                              int odd)
```
    Interleaves the first 32 bits of each long value Adapted from: http://graphics.stanford.edu/~seander/bithacks.html#InterleaveBMN
  - deinterleave
```
public static long deinterleave(long b)
```
    Extract just the even-bits value as a long from the bit-interleaved value
  - flipFlop
```
public static long flipFlop(long b)
```
    flip flops odd with even bits
  - zigZagEncode
```
public static int zigZagEncode(int i)
```
    Same as zigZagEncode(long) but on integers.
  - zigZagEncode
```
public static long zigZagEncode(long l)
```
    Zig-zag encode the provided long. Assuming the input is a signed long whose absolute value can be stored on n bits, the returned value will be an unsigned long that can be stored on n+1 bits.
  - zigZagDecode
```
public static int zigZagDecode(int i)
```
    Decode an int previously encoded with zigZagEncode(int).
  - zigZagDecode
```
public static long zigZagDecode(long l)
```
    Decode a long previously encoded with zigZagEncode(long).

Class BitUtil

Method Summary

Methods inherited from class java.lang.Object

Method Detail

pop_array

pop_intersect

pop_union

pop_andnot

pop_xor

nextHighestPowerOfTwo

nextHighestPowerOfTwo

interleave

deinterleave

flipFlop

zigZagEncode

zigZagEncode

zigZagDecode

zigZagDecode